Alteration of coastal productivity and artisanal fisheries interact to affect a marine food web

Abstract

Top-down and bottom-up forces determine ecosystem function and dynamics. Fisheries as a top-down force can shorten and destabilize food webs, while effects driven by climate change can alter the bottom-up forces of primary productivity. We assessed the response of a highly-resolved intertidal food web to these two global change drivers, using network analysis and bioenergetic modelling. We quantified the relative importance of artisanal fisheries as another predator species, and evaluated the independent and combined effects of fisheries and changes in plankton productivity on food web dynamics. The food web was robust to the loss of all harvested species but sensitive to the decline in plankton productivity. Interestingly, fisheries dampened the negative impacts of decreasing plankton productivity on non-harvested species by reducing the predation pressure of harvested consumers on non-harvested resources, and reducing the interspecific competition between harvested and non-harvested basal species. In contrast, the decline in plankton productivity increased the sensitivity of harvested species to fishing by reducing the total productivity of the food web. Our results show that strategies for new scenarios caused by climate change are needed to protect marine ecosystems and the wellbeing of local communities dependent on their resources.

Climate change in the coastal ocean: shifts in pelagic productivity and regionally diverging dynamics of coastal ecosystems

“…While geographical displacements in species distribution are common and have been a primary focus of ecological climate change studies [34,35], the vital population rates that allow species to persist, grow and, in some cases, maintain fisheries, are also expected to be altered as a consequence of climate-induced changes in primary production [43,44] and circulation patterns [2] and have been less documented. Indeed, among the many climate-stresses affecting the global oceans, changes in primary production are probably the most pervasive, potentially imperilling trophic amplification in food webs and threatening food production and global fisheries [44–46]. Our results show that both increasing and decreasing changes in pelagic phytoplankton productivity, forced by SPA poleward migration and intensification [11], are associated with geographical changes in larval replenishment of benthic populations of two common barnacle species.…”

“…In conclusion, rates of positive and negative population changes have occurred, apparently induced by bottom-up productivity effects and modulated by recruitment–stock dynamics, linking pelagic and benthic ecosystems. As suggested by model results, similar bottom-up effects should be affecting most species with plankton-feeding larvae, including fished species [46,48]. This implies that along large section of HUE productivity of fish stocks should increase, and fisheries effort should be displaced equatorward, contrasting with the opposite prediction based on upwelling-driven transport and oxycline position in the northern HUE [54].…”

A Framework for Simulating Ecosystem Effects in Data-Poor Small-Scale Fisheries Using Science-Based and Local Ecological Knowledge-Based Models

“…However, the attack and error scenarios allowed us to understand not only the role of the target species but also the broader vulnerability and resilience of the food webs (Solé and Montoya, 2001;Dunne et al, 2002) to fishing or environmental impacts on specific components (Ávila-Thieme et al, 2021). Although the attack and error scenarios represent extreme situations such as the total removal of functional groups, which is unlikely to be caused by fishing or environmental changes in the short term, these scenarios allow us to place into context both aspects, i.e., the role of target species and the vulnerability of the food web.…”

“…On the other hand, because fisheries are commonly related to negative impacts on marine ecosystems, particularly on the target and incidental species, effects may not necessarily occur at the whole level of an ecosystem's food web. For this reason, it is relevant to use modeling tools to analyze the vulnerability of ecosystems to biodiversity loss as a consequence of human impacts (Dunne et al, 2002;Allesina et al, 2009;Marina et al, 2018), such as fishing (Ávila-Thieme et al, 2021). However, although the effects of fishing can modify the structure and function of the ecosystem, changes in the productivity of the system due to other factors can produce similar effects, and moreover, the interaction of different factors jointly affects ecosystems (Ávila-Thieme et al, 2021).…”

The Role of B Companies in Tourism towards Recovery from the Crisis COVID-19 Inculcating Social Values and Responsible Entrepreneurship in Latin America

“…Moreover, B Corps go beyond the notion of Corporate Social Responsibility, as they contain, as part of their business operations, a social purpose [19,20]. This social phenomenon is now considered one of the biggest emerging business ideas of modern times and is an important part of our consumer society [21][22][23]. It includes commercial, leisure, pleasure, enjoyment, professional goals and other activities related to the time people spend away from their usual residences [16].…”